This invention relates to bookbinding, and more particularly, to a tape employed in a microwave bookbinding system.
Typical current Bookbinding systems include equipment that utilizes heated surfaces which comes into contact with a tape substrate coated with a hot-melt adhesive, as shown for example, in U.S. Pat. No. 3,928,119 where an adhesive bearing strip is driven, by relative motion between a stack of sheets and spaced platens, between the heated platens by the stack. In machines of this type, the heated platens are subsequently moved toward each other to move and press the adhesive strip to the stack of sheets. A moisture proof binding tape for edge binding pages to form a book is shown in U.S. Pat. No. 5,213,871 that consisting of a non-permeable temperature resistant foil layer covering one side of the backing strip forming a moisture barrier, a high temperature steam resistance adhesive between the foil layer and the backing strip to secure the foil layer to the backing strip, and a relatively thick central stripe of high tack heat activated adhesive flanked by relatively thin side stripes of low tack heat activated adhesive on the foil layer, the central adhesive stripe comprising a non-hygroscopic adhesive. Some disadvantages of systems of this type include: the high energy consumption (i.e., maintained at a specific temperature, for example, about 400xc2x0 F.); the relatively long dwell time to fluidize the adhesive; and the difficulty in recycling bound books. The above-mentioned patents are incorporated herein by reference to the extent necessary to practice the present invention.
Thus, there is still a clear need for an improved bookbinding system that has a lower binding time, is cheaper in cost per bind, and is more energy efficient.
In one aspect of the invention, a tape is disclosed that includes a water soluble adhesive that surrounds the spine portion of a book to be bound a microwave bookbinding system. Upon activation of a microwave heater, the adhesive reacts to microwave energy to penetrate into edges of pages of the book to bind them together in the book.
In another aspect of the invention, a binder tape is disclosed that comprises a thin dielectric film which converts microwave energy into thermal energy, thus causing a layer of glue to melt and promote the binding of the page edges and flaps of books around which the binder tape is mechanically wrapped.